Insulin action and resistance are dependent on a GSK3β-FBXW7-ERRα transcriptional axis

Insulin resistance, a harbinger of the metabolic syndrome, is a state of compromised hormonal response resulting from the dysregulation of a wide range of insulin-controlled cellular processes. However, how Insulin affects cellular energy metabolism via long-term transcriptional regulation and whether boosting mitochondrial function alleviates Insulin resistance remains to be elucidated. Herein we reveal that Insulin directly enhances the activity of the nuclear receptor ERRα via a GSK3β/FBXW7 signaling axis. Liver-specific deletion of GSK3β or FBXW7 and mice harboring mutations of ERRα phosphosites (ERRα^3SA) co-targeted by GSK3β/FBXW7 result in accumulated ERRα proteins that no longer respond to fluctuating Insulin levels. ERRα^3SA mice display reprogrammed liver and muscle transcriptomes, resulting in compromised energy homeostasis and reduced Insulin sensitivity despite improved mitochondrial function. This crossroad of Insulin signaling and transcriptional control by a nuclear receptor offers a framework to better understand the complex cellular processes contributing to the development of Insulin resistance.